TDAmapper: Analyze High-Dimensional Data Using Discrete Morse Theory

Topological Data Analysis using Mapper (discrete Morse theory).
Generate a 1-dimensional simplicial complex from a filter
function defined on the data: 1. Define a filter function (lens) on the
data. 2. Perform clustering within within each level set and generate
one node (vertex) for each cluster. 3. For each pair of clusters in
adjacent level sets with a nonempty intersection, generate one edge
between vertices. The function mapper1D uses a filter function with
codomain R, while the the function mapper2D uses a filter function with
codomain R^2.